1. Field of the Invention
The present invention relates generally to a damping valve with adjustable damping force for a vibration damper. The vibration damper includes a cylinder filled with damping medium. In the cylinder a piston rod with a piston is contained so that the piston rod can move axially and the piston can divide the cylinder into two working chambers. The damping valve can be adjusted by means of a magnet coil or solenoid in connection with an armature. The damping valve can have an emergency operating setting.
2. Background Information
A known damping valve similar to that described above is disclosed in German Patent No. 42 08 886 A1. The essential advantage of the valve is that a damping force characteristic which differs from the maximum hard setting can be provided as the emergency operating setting. One problem of these known damping valves is that the magnitude of the flow cross section in the emergency operating setting is, to a significant extent, dependent on the tolerances of some of the components, whereby the effect of these tolerances is cumulative.
A known damping valve as described in German Patent No. 39 17 064 A1 does not have this problem. In this damping valve, a separate bypass was provided which is active in the emergency operating position. The emergency operating setting is defined by two-seat valves, whereby one valve seat, in terms of its action, can be considered a hydraulic switch.